18th century jailer's flintlock key gun.
https://s3-us-west-1.amazonaws.com/h...o_fullsize.jpg
Previously:
https://www.homemadetools.net/forum/...314#post154264
https://www.homemadetools.net/forum/...6956#post84708
https://www.homemadetools.net/forum/...171#post126210
